"I think he's so sweet … but I will also say they're teenagers and I really can't keep teenagers straight," Kardashian Odom, 28, told Seacrest. "You just never know. Everything is up and down, but they're definitely best friends."

"I was in L.A., we were all hanging out. Then I went to New York and she came too, then she came here [to London] and surprised me, so that's pretty baller," the young star said. "She's one of my best friends. It's pretty awesome."

A source close to the pair told Us that the spring romance is "new," but the duo have "been friends forever."

Prior to Smith, Jenner was linked to Australian pop star Cody Simpson, though she denied the reports at the time, telling Seventeen in September 2012 that "Cody and I are just good friends. We can say that as much as we want and people will still listen to gossip."